Device for starting races



April 3, 1951 B. B. LOVELESS ETAL DEVICE FOR STARTING RACES 4 Sheets-Sheet 1 Filed Sept. 23, 1949 0 0 1 7 z 1 4a WW4 4 4 1 Q. 2 I ima 1R 1 g 4 m a F 2 x 0 9 4 3 4 4 4 83M 4 w z Rzc mm J. HLHA April 1951 B. B. LOVELESS ETAL DEVICE FOR STARTING RACES 4 Sheets-Sheet 2 Filed Sept. 23, 1949 m w A d v. m8 m m April 3, 1951 B. B. LOVELESS EIAL DEVICE FOR STARTING RACES 4 Sheets-Sheet 3 Filed Sept. 23, 1949 To CONTROL manta-I I FIG. 9

w sm mi N Nan N m m m J1 ,5 AM wo .AY g J ww A April 3, 1951 B. B. LbvELEss EIAL DEVICE FOR STARTING RACES Filed Sept. 23, 1949 4 Sheets-Sheet 4 GUN CONTROL EEL Fxon CONTROL CIRCUIT FIG. 10

IN V EN TOR R1 cHA/w JALHAND, Ens/L J. JAMPLE flora 5. L 01/54 555 BY W JMm w vd .4r-romvs Y i iC DEVICE FOR STARTING RACES Boyd Bryan Loveless, Richard Jackson Alhand, and Basil Stafiord Sample, Danvillc, 111., as-

signors to Electric Eye Equipment Company,

Danviile, lit, a corporation of Delaware 7 1 Claim. 1

This invention relates to detectable signals for use in the starting of foot races of various sorts, swimming races, and any other such event in which accurately timed startin signals are required.

Many times, important potential record performances and important races have been lost because a contestant who might have set the record or won the race was handicapped by a bad start. Most races are started by a man appointed as the starter who gives spoken commands and manually fires a starting gun. The timing of these signals therefore varies greatly from one starter to another and even the same man, no matter how experienced he may be, can not always be consistent in the timing of his startin signals. Consequently, in any race started orally, there is high probability of one or more contestants either starting before the gun is fired or being not quite ready to start when the gun is fired. automatic starting devicedescribed herein, the signals are accurately timed and are, therefore, always the same. This device can be used in practice by all contestants as Well as in a charmpionship contest thus enabling all contestants to become accustomed to the timing of the starting signals. This gives each contestant a fair and equal chance to start at the exact instant the starting gun is fired.

It is, therefore, an object of this invention to \Nith the provide an automatic device which speeds the running of various events during a track meet.

By always providing consistently timed signals which the contestants can anticipate, most fouls or false starts are eliminated. This eliminates the time required for a second liningeup of the contestants and a second start. Also by climinating false starts, the energy of the contestants is conserved for the race itself enabling each contestant to give his full ability in the race.

We accomplish the above object as well as others which will become apparent from the demove across the starting line before the start of a race. 7

Other important advantages of our invention are that the device is small, compact and lightweight making it easily portable to various starting points. It is usable atany point on a race 2 track and can even be used for staggered starts where the starting line runs diagonally across the track. Because of its ease of operation, it can be operated by an assistant thus relieving a highly expert race official from the duties of timing the starting signals and of calling back contestants who jump the gun. This allows the ofiicial to concentrate fully on the other important details of his job assuring better and fairer races for all concerned. Also, when our device is used in practice, it can be operated by the runner himself, eliminating the need for an experienced starter and thus releasing the coach for other duties.

Other advantages and objects of our invention will become apparent'by referring to the drawings in which:

Figure 1 illustrates the positioning of the device in relation to a track,

Figure 2 is a perspective view of the control box,

Figure 3 is a cross-sectional view in elevation of the control box showing the arrangement of the various signalling means,

Figure 4 is a perspective view partly in crosss'ection illustrating photoelectric signalling and receiving means used for'preventing a false start,

Figure 5 is a detailed view of the lens arrangement which is part of the optical system,

Figures 6 and 8 are details in elevation and cross-section of the gun firing mechanism,

Figure '7 is a detail of the gun firing mechanism as viewed from the top,

Figure 9 illustrates the electronic circuit for amplifying the signals received by the phototube,

electrical power which usually consists of a 6 volt storage battery. During the course of operation, a light beam 5, originating in the control box I, is projected across the track, close to and parallel to the starting line a, to the mirror box 2 which then reflects the light beam back to a light sensitive device in the control box l. i

In operation, the depressing of a start button by the operator initiates action of the device. Immediatelyupon starting, a bell begins to ring. This signal is comparable to the usual spoken command, on your mark. The bell continues ringing for a period long enough to allow the contestants to get into position. At the end of this period, the bell stops ringing and a buzzer is energized to indicate the usual get set command. After an interval as specified b the contest rules, the buzzer stops and a gun is fired to indicate the exact starting time of the race. If, at any time after the get set buzzer sounds, and before the gun is fired, a contestant interrupts the light beam, a horn will blow indicating a foul. A push button is provided for manually sounding the foul hor-n.

The mechanical construction of our invention will be described first. The control box LFigure -l, is illustrated in more detail in Figure 2. It is a steel box 8 supported on legs '1'. Two holes are provided in the side of the box, the lower one 8 for the light beam which is projected across the race track and the upper one 9 for the image of the beam which i reflected back to the control box. The top surface of the box serves as the control panel to. On it are mounted .pushbuttons it, Hi, l and i6, switch ll, observation window l8, and knobs I9, 26 and 2!. The functions of these controls are described later. A tube 4 l extends upward from the box and carrie the gun assembly 12. This tube is of telescoping construction so that the gun may be raised above observers standing nearby and thus protect against personal injury from the firing of the gun. This feature also places the gun in a position where it can be clearl seen by timers and other oihcials of the race.

Inside the control box, as shown in Fi .re 3, are mounted a bell 22, a buzzer 23, a horn 2e, and power supply equipment 25. The signal timer 26, containing timing cams H2 through lie inclusive, switches Ill], lll, H6 and ill and motor is; relays 2? and 28; the light source and light beam chopper unit 2% the .phototube and amplifier assembly 3 l the aligning mirror 3?. and the lens assembly 33 are also included in the control box.

The parts in the control box l associated with the optical system and with the mirror box assembly 2 are shown in more detail in Figure These parts are the light source and beam chopper unit 29, the lens assembly 33, the phototube and amplifier unit 3 I, the aligning mirror 32 and the mirror box 2. Light is generated in the electric lamp 36. A chopper disc 35 is interposed between lamp 3% and the lens 36. The chopper disc 35 contains evenly spaced holes 3? placed in a circle around the center of the disc 35 near the periphery of the disc. These holes 37 are so placed that as the disc is rotated by the chopper motor 33 they successively pass through a line between the filament 39 of the lamp 3d and the center of the lens 36. Thus, light from the lamp filament 3% passes to the lens 35 and out of the control box I only when a hole 3'. in the chopper disc 35 is aligned between the lamp and the lens Rapid rotation of the disc 35 then causes the light beam 5 leaving the control box 5 to turn on and off at a rapid rate.

The light beam 5 is thus chopped for the purpose of giving the light beam a pulsating characteristic which permits it to be a distinguished from other light which falls on the phototube The amplifier circuit can then be made responsive only to rapidly pulsating light and thus it is not affected by other light falling on the phototube 30.

The lens assembly 33 is adjustable in three directions to provide for focusing and aiming the light beam 5. These adjustments are shown in detail in Figure 5.. The two lenses 36 and are fastened to the lens plate ill. The lens plate 5! is fastened to the lens assembly bracket 12 in such a manner that the lens plate t! is free to move vertically relative to the bracket 42. Springs Q3 and 3 1 are compressed between collars t5 and 36 respectively on guide rods 5? and 58 respectively and the upper flange 3-9 of the lens plate ll. Guide rods ll and to hear at their lower ends against the lens assembly bracket G2 and thus the springs 13 and 3 3 tend to force the lens plate 5i upward against the vertical adjustment rod 59. The vertical adjustment rod to is threaded and its threads engage those of nut 5i which is fastened to the guide tube 52 which in turn is fastened to the control panel lil. The adjustment rod 58 extends through the guide tube 52 to the outside of the control panel it where a knob 2! is attached. The adjustment rod 5*] can be screwed up or down through the nut 5i by turning the knob 2i. As th adjustment rod 50 is screwed down, it forces the len plate ti downward against the force of springs 33 and M. Screwing the rod upward releases the lens plate ll and the force of springs and Ed is allowed to move the lens plate M upward. As the lens 36 is thus moved upward and downward, the light beam 5 is aimed higher or lower.

The lens mounting bracket 32 is attached to the base plate 53 by a single bolt 5 The bracket d2 can rotate around this bolt 54 as a pivot. A shaft 55, carrying an eccentric cam 56 which engages a slot 51 in the lens bracket E2, is mounted between the base plate 53 and the control panel iii. As the upper end of the shaft 55 is rotated by turning knob ill, the eccentric cam 55 pushes against one or the other side of the slot 51 forcing the bracket 52 and the lenses 3% and so to pivot back and forth around the bolt 5d. Thus as the shaft 55 is turned, the lenses 3e and ii] are moved sideways and, as the lenses 3e and ii are moved sideways, the light beam. 5 is directed to one side or the other.

Focusing of the image reflected to the phototube is accomplished by loosening the pivot bolt 54 and sliding the lens assembly bracket 32 relative to the base plate 53 in the direction of the slot 58 into which the pivot bolt 55 fits. The pivot bolt is provided with a shoulder so that it can be tightened relative to the base plate, fixing the focus adjustment, while leaving the lens bracket 32 free to oscillate around the pivot The mirror box 2, Figure 4, consists of a housing 3! provided with legs 92. In the front of the housing are two holes for passage of light. The light beam 5 from the control box i enters through the lower hole 93 and is reflected back to the control box through the upper Sl. Inside the housing in is an assembly as of three plane mirrors each perpendicular to each of the others. In this manner, they are positioned relative to each other as are the three sides at a corner of a cube. The reflecting surfaces 95 of this cubical corner of mirrors are on the inside. With this arrangement a light beam striking one of the mirrors will always be reflected back by one of the other mirrors in a direction parallel to the incident beam but the reflected will be displaced from the incident beam by a distance depending on the point at which the incider beam strikes the first mirror. The mirrors are arranged relative to the holes $3 and 5:3 in the housing ill such that whenever the light beam 5 from the control box is centered on the lower hole 93 in the mirror box and enters at approximately right angles to the plane of the holes 93 3 and 94 the reflected beam will pass through the upper hole 94 in the mirror box and fall on the upper hole 9 Figure 1 in the control box I Figure 1. Thus the only adjustment necessary to correctly align the two boxes after they have been set in approximately correct positions is to direct the light beam to the lower hole 93 in the mirror box. This mirror arrangement thus greatly facilitates the light beam adjustment required to correctl center the beam on the phototube.

To facilitate the aiming and focusing of the ight beam 5, the alignment mirror 32 (Figure 4) is provided. This mirror 32 is hinged to its mounting bracket 59 and it is provided with a pull rod 68 which extends upward through the control panel In. Knob i9 is attached to the upper end of rod 89. When the pull rod 60 is pulled upward, the mirror 32 swings into a position which intercepts the light beam 5 coming into the control box through the upper lens 40. The mirror 32 then reflects the light beam 5 upward toward the control panel it. An observation hole I8 is provided in the control panel ill for observing the mirror 32. The mirror 32 is so positioned that when it properly reflects the light beam 5 to the observation hole i8, it is indicated that the light beam is properly directed to the mirror box 2. Then. when the mirror 32 is allowed to drop, by releasing the pull rod 69, back into its normal position out of the path of the light beam, the light beam will fall correctly on the photo-tube 38 in the phototube amplifier unit 3|.

The gun assembly !2 (Figure 2), which is mounted in the upper end of the gun tube I I, is shown in detail in Figures 6, 7 and 8. Refer first to Figure 6 which shows, in section, the upper portion of the gun assembly and to the top view in Figure '7. The entire assembly is mounted to the gun frame Bl which in turn is fastened to the gun tube ii. The cartridge holder 62 is attached to the gun frame 5! by a screw 63 which also acts as a pivot for the cartridge holder 52. When the cartridge holder 52 is closed, the ball 54 of spring catch 65 centers itself in a hole 66 in the gun frame iii to hold the cartridge holder 522 closed. In; this position, the cartridge chamber El is aligned with the bore of the gun barrel 68. Thus, by rotating the cartridge holder 62 about its pivot 63, the cartridge chamber 51 can be swung out of the gun frame 6 i. A blank cartridge can then be inserted and, when the cartridge holder 52 is again closed, the cartridge will be correctly positioned between the firing pin 69 and the barrel As a safety measure, the cartridge chamber 67 is especially made so that only blank cartridges can be inserted.

The upper end of the firing pin 69 slides in a hole in the center of the gun frame 6|. A guide plate H3 is rigidly fastened to the gun frame 5| by three supporting rods I! (only one is shown for simplicity of drawing). The lower end of the firing pin 59 slides in a bearing sleeve 12 afiixed to the guide plate 1! Spring 13, com,- pressed between the guide plate l9 and the cocking arm 14 which is fastened to the firing pin 69, tends to force the firing pin 69 upward. The cocking arm 14 in its extreme upward position contacts the bottom surface of the gun frame 6| to limit the upward travel of the firing pin 69. In this extreme upward position, the tip of the firing pin 69 protrudes into the cartridge chamber (57. Thus, when a cartridge is placed in the cartridge chamber 61 and the firing pin 69 is travelling upward toward the cartridge, the tip can roll radially from the firing pin 69.

6 of the firing pin '69 will contact the cartridge and cause it to fire or detonate just before the extreme upward position of the firing pin 69 is reached.

An electrical switch 16 is. mounted on the gun frame. The contacts of this switch 16 are such that they open when the plunger 'l'i is released and close when the plunger H is depressed. An

provides the force for releasing the firing pin 69 from its cocked position is rigidly mounted to the guide plate 10 by three supporting members 83 (only oneis shown for simplicity of drawing). The armature 3! of the solenoid i9 is connected to the locking sleeve 82 which slides over the bearing sleeve 12 which in turn is fixed to the guide plate '16. A flange E3 on the locking sleeve 82 contains holes which slide over the solenoid supporting members 88. Springs 84 fit over the solenoid supporting members 39 and are compressed between the solenoid l8 and the flange 83 on the locking sleeve 82. Thus, these springs tend to force the locking sleeve 82 and the solenoid armature 6i upward. The bearing sleeve 72 contains two holes through which two balls 85 The balls 85 are restricted in movement on the inside of the bearing sleeve 72 by the firing pin 653 and 4 on the outside by the locking sleeve 82. The lockingsleeve 32 is bored so that three portions of its inner surface have three different diameters. One diameter 81 extending from the lower end up the greater portion of the length of the locking sleeve 82 is such as to provide a sliding fit over the bearing sleeve E2. The second diameter 88 extending a short distance farther toward the upper end of the locking sleeve 32 is slightly larger and is such that it will slide over the ba11s85 only when they are moved to protrude a considerable distance into the bore of the bearing sleeve 7'12. The third bore diameter 89 at the upper end of the locking sleeve 82 is still larger such that, when the locking sleeve 82 is pulled downward and the balls 85 are moved radially outward and rest against the sleeve 82 at this diameter, the balls 85 will not protrude into the bore of the bearing sleeve 12. Thus, when the gun is cooked by manually moving the cooking arm 15 and firing pin 69 downward against the force of the firing spring 13, the balls 85 ride against the firing pin 69 until the firing pin 69 v has been moved downward far enough to bring the groove 88 (which is cut in the firing pin), opposite the balls 85. At this point, the springs 84 force the locking sleeve 82 upward which in turn pushes the balls 85 inward so that they protrude into the groove 90 in the firing pin. With the balls 85 thus protruding, the locking sleeve 82 moves upward due to the force of springs 84 bringing the second bore 88 in the locking sleeve 82 up opposite the balls 85. This smaller bore 88 then prevents movement of balls 85 back out of the groove 90 in the firing pin. The balls 85 then obstruct the sliding of the firing pin 69 through the hole in the bearing 7 sleeve 52 and thus they hold the firing pin 69 in the downward or cooked position.

When electrical power is applied to the sole noid t9, the armature 8i and the locking sleeve 82 are pulled downward. This movement of the locking sleeve 82 brings the largest bore diameter 89 in the locking sleeve 82 opposite the balls 85. The balls 85 can then be pushed outward as the firing pin 69 moves upward. The firing pin 69 is then free to be pushed upward by the spring it. Thus, energization of the solenoid "9 releases the firing pin 69 and causes firing of the gun.

The electronic circuit of the phototube and amplifier unit 3! (Figures 3 and 4) is shown schematically in Figure 9. As described pr.- viously, a beam of light, pulsatin in intensity, normally is directed onto thephototube 38. The phototube 3G is connected in series with a resistor 91 between a source of direct voltage having positive terminal 13+ and a negative terminal at ground. The electrical resistance of a phototube varies inversely with the amount of light striking it and consequently the current flowing through the phototube 3d and the resistor 91 varies directly with the amount of light falling on the phototube 38. Since normally the light intensity is varying, this current through the phototube as will vary correspondingly and produce a correspondingly varying voltage at the junction between the phototube 38 and resistor 9'5. This varying voltage is transmitted to the control grid 98 of the amplifier tube 99 through a condenser Hit. The filament or cathode is! of the amplifier tube 99 is heated by the flow of electrical current from another power source having positive terminal A-}- and negative terminal at ground.

Whenever the voltage On the control grid (98) is more positive than the voltage on the cathode H] l current will flow between grid 98 and cathode IUi. Thus at the peak of the positive going signal a slight amount of grid current flows charging the coupling condenser It'll negatively on the grid end. This means that the positive pulsating voltage produced by the phototube will appear as pulsating negative voltage on the grid 98 of the amplifier 99. The condenser lilli does not charge and discharge appreciably through the grid resistor i132 when the pulsating light beam falls on the phototube because the electrical resistance of this resistor I92 is relatively high. Thus, considerably more time is required for chargin and discharging of the condenser 698 through this resistor i632 than is allowed between the applied pulses of voltage.

Maximum current flows through the amplifier tube 99 when its control grid as voltage is maximum and the current decreases as the grid voltage goes negative with respect to the voltage on the cathode i8! (ground). Thus the negatively pulsating voltage applied to the control grid 98 causes a pulsating current to flow through the amplifier tube 99. The inductance of the relay coil m3 and the capacity of the condenser its connected across the tube tend to keep the current flowing through the relay coil I53 constant at a value which is an avera e of the maximum and minimum flowing in the amplifier tube and which is too small to operate the relay.

Now, when the light beam is interrupted and the pulsating light no longer falls on the phototube 30, the coupling condenser Hi8 then discharges through the resistors m2 and 3'? and the voltage of the control grid 88 of the amplifier tube as rises to ground potential. The amplifier tube 99 then conducts a maximum of current steadily. This discharges the filter condenser i 35 and thi maximum current then flows through the relay coil I03 causing it to close a pair of normally open contacts Hi5 the function of which is described later.

The control circuit is illustrated in Figure 10. This diagram shows the electrical connections between the operating pushbuttons and switches, relays, the timer, and the various devices which are operated electrically. All switches as shown in this diagram are in their normal or at rest positions such as would be the case just before starting the device for operation.

The circuit is supplied by a source of electrical power having a positive terminal 5 l3 and a negative terminal I29 which is grounded. Depressing the start pushbutton 13 applies power through contact [535 on relay 23 to the timing motor N38, to the 13+ terminal of the amplifier unit 3!, and further through contact Hi9 0n relay 2'! and contacts iii] and ill on the timer unit 26 (Figure 3) to the bell 2:2. The bell 2.2, thus energized, begins to ring. The timer motor I38 then runs rotating the four timing cams H2, H3, H4 and H5 which are associated with switches lit, Il'l, lit and ill respectively. Since the A-{- power to the phototube and amplifier unit 3| is not yet turned on, this unit 3! does not start operating immediately. Soon after the timer motor ltd begins to run, earn 5 l2 operates switch H5. This switch 556 then shorts across the start pushbutton l3 permitting release of the pushbutton IS without stopping operation of the device.

After the bell 22 has rung for almost its full period, during which time contestants are getting to their starting places, cam H3 operates switch ill. Power is then supplied'through switch II! to the A+ terminal of the phototube and amplifier unit 3!, and also through switch H! to the light source 34 and chopper motor 38. This turns on the light beam and the amplifier unit 3|. The turning on of these devices is delayed as described to allow time for contestants or others to get out of the path of the light beam. This prevents obtaining a foul signal during the relatively long period during which the contestants are movin to their places.

Next, cam i it operates switch i i l which opens the circuit to the bell 22 and connects power to the buzzer 23. This causes the bell 22 to stop ringing and starts operation of the buzzer 23. The buzzer 23 then continues throughout the get set period until cam il operates switch H0 which then opens the circuit to switch HI and the buzzer 22 and energizes the solenoid is in the gun assembly 12 (Figure 2). The gun solenoid l9 then causes firing of the gun as previously explained. Just as the gun is fired, switch '56 is closed by the upward position of the firing pin ts (Figure 6) as described previously. Power is then supplied through switch it to the coil of relay 2? which in turn operates contacts sea and H8.

Whenever a runner interrupts the light beam, while the phototube and amplifier unit is turned on, contact @535, l fl'llCh is operated by relay coil (i i-i the phototube and amplifier circuit (Figure 9) will be operated. Thus when the gun is fired, contact i523, operated by relay coil 21 removes power from contact Hi5 so that operation-of relay 1% the interruption of the light beam by the runners will not then of the foul signal 24.

As the cam motor I08 continues to run, cams I I3, H4 and H5 will, soon after the firing of the gun, return switches III, III) and III respectively to their original positions. 'None of the signals will then be operated due to the open position of contact I09 operated, as described above, by relay coil 2'1. After all the cam switches are returned to normal, cam H2 releases switch M6 to its original position. This deenergizes and stops the cam motor I08, removes B+ power from the phototube and amplifier unit 3|, and deenergizes relay coil 2! allowing contacts I09 and H8 to return to their normal positions. The unit is then completely reset, shut-off and ready for another operation.

As mentioned above, if the light beam is interrupted, the phototube and amplifier unit 3| will cause operation of relay coil I03 (Figure 9) which in turn operates contact I05. When this occurs while contact I I8 is in its normal position (before the gun is fired), power will be conducted through switch H6, contact H8, and contact I05 to the foul horn 24 and also to relay coil 28. Sounding of the horn 24 then indicates that the light beam has been interrupted while energization of relay coil 28 causes operation of contacts I05 and I01. Contact I06 then opens the circuit to the cam motor I08 causing it to stop. Contact I06 also closes the circuit to relay coil 21 which in turn operates contacts I09 and I I8. The other contact I01 operated by relay coil 28 closes a second circuit to the horn 24 and also to its own coil 28. Thus the horn sounds continually and relay coil 28 remains energized after contact I05 has returned to its normal position. The horn 2 3 will thus continue to sound until it is shut off by the operator. Pushbutton I 4 is normally closed and thus completes the circuit to relav coil 28. Operation of this pushbutton I4 breaks the circuit to relay coil 28 which in turn restores contacts I116 and I! to their original positions. When contact I is thus returned to its normal position, power is again applied to the timer motor I08 causing it to run until all cam switches H0, III, IIS. and II? are again reset as previously described. Returning of contact I 01 to its normal position o ens the circuit to the foul horn 24 turning it oiT and also breaks the circuit from the power source plus terminal to relay coil Contacts I09 and II 8 operated by relay coil 2! remain in their operated positions as previously described until the timer cams H2, H3, IE4, and H5 are reset. With contact I09 thus open, neither the bell 22, buzzer 23, nor the gun i9 will be operated during the resetting period. Also, with contact H8 in its operated position, relay coil 2'! will be energized until switch H6 opens; and the power supply to contact I05 will be held open so that another interruption of the light beam while the timer motor I03 is resetting will not cause a second operation of the horn.

A pushbutton I 5 is provided to allow the operator to sound the foul horn 24 at any time he may desire. This pushbutton I5, when operated, closes a circuit from the power source positive terminal directly to the horn 24. This also energizes relay coil 28. Thus, if the pushbutton I5 is operated while timer switch IIG is operated (during the course of operation oi the cause sounding device), the timing cycle will be stopped and other operations will occur just as they did when the horn 24 was energized by contact I05 due to interruption of the light beam as described above. Operation of pushbutton I5 at a time when the timer switch H0 is in its normal position will cause energization of relay coil 28 and associated operations; but, since switch H6 is in its normal position, power will not be conducted through contact I0! to the horn 24 and relay coil 28. Thus, in this case, the horn will remain energized only as long as pushbutton I5 is held closed.

Another pushbutton I0 is provided for manually energizing the gun solenoid IB which results in firing the gun. Closing of this pushbutton I6 conducts power from the switch H0 directly to the solenoid 19 as long as switch II 0 is in its normal position. Thus the gun can be fired manually only when the timer is reset. This prevents firing of the gun by accidentally touching pushbutton I6 while the timer is in operation. This feature allows firing of the gun to indicate the last lap of a long race as is the general practice.

A switch I1 is provided for use during the setting-up of the device. B operating this switch, the light source 34 and chopper motor 38 are turned on independently of the rest of the device. This facilitates aiming and adjusting of the light beam by keeping the light source on continuously without the sounding of any of the signals.

We claim:

An automatic starter for races comprising in combination three different audible signalling means and switching means for each connected therewith, an electric circuit connected with said Si nalling meanshaving a source of power, separate timing means connected in sa d circuit to operate each of said switching means such that said si nalling means are actuated in succession at different time intervals, a fourth audible signalling means connected through other switching means to said circuit and actuated when a false start is made comprising means projecting a beam of li ht across the starting line. means chopping said light thereby creating a pulsat ng beam. photoelectric means positioned to receive said li ht ulses, electronic means connected with said photoelectric means in said electric circuit responsive solely to an interruption of said pulsating light beam including relay means simultaneously actuating the switching means for the last actuated signalling means and thereby actuating said fourth signal means when a false start is made, and means for manually initiating and resetting the operation of said timing means, said switching means and said audible signalling means.

BOYD BRYAN LOVELESS. RICHARD JACKSON ALHAND. BASIL STAFFORD SAMPLE.

REFERENCES CITED UNITED STATES PATENTS Name Date Hite June 29, 1943 Number 

